1. Field of the Disclosure
The present disclosure relates generally to the field of material handling. More specifically, the present disclosure is directed to a wheel for use in a parcel-handling flow shelf device, and a flow shelf including one or more of such wheels.
2. Brief Discussion of Related Art
A roller bed, or carton flow shelf, for example as marketed by the Assignee of the instant application, is a parcel handling device in which a plurality of wheels or rollers of equal diameter are mounted for rotation around generally aligned axles that are in a common axis plane. Accordingly, a parcel placed on the flow shelf will rest on a transit plane that is offset from the axis plane by the radius of the wheels or rollers, the tangent with the wheels or rollers.
Commonly, the wheels or rollers rotate freely around their respective axles. However, in certain instances some or all of the wheels or rollers in a flow shelf may be driven to move parcels. In a free-rotating flow shelf, to transit parcels along the flow shelf the parcel may be pushed, for example by a human operator or a machine. Alternately, the flow shelf may be mounted at an angle relative to horizontal. Thus, the effect of gravity will influence a parcel placed on a high side of the angled flow shelf to transit towards the low side. This gravity feed effect is resisted by friction between the wheels or rollers against their axles, and also by the inertia of the wheels or rollers themselves.
In order for a flow shelf to operate with maximum efficiency, the wheels or rollers must roll freely with a minimum of frictional resistance. One expedient solution would be to lubricate the rollers and axles. However, in the real application environment for flow shelf devices, e.g., warehouses, airborne particulate matter are trapped by viscous lubricants. In the long term, lubrication may have a net negative effect on the freedom of wheel or roller motion unless time, labor and expense is incurred for continual cleaning and maintenance.
An improved solution for free motion of the rollers compared with the present state of the art therefore remains wanting.